c++ What's the output of this function?

Question

the output of this program should be this:

Can anybody explain why the output of this main is:

F1/2 F2/3 F5/4 F0/1 F0/1 F0/1 F0/1 F0/1

K0/1 K0/1

K?/? K2/3 K1/2

can you explain how we get the last 2 lines ? thanks

the constructor is initialize like this in fraction.h

Fraction(int n=0, int d=1);

 /* fraction.cpp */
#include "fraction.h"
#include <iostream>
using namespace std;
Fraction::Fraction(int n, int d)
: numerateur(n)
{
dedominateur = d;
cout << "F" << n << '/' << d << ' ';
simplifier();
}
Fraction::~Fraction(){
    //cout<<"destructeur";
cout << "K"
<< numerateur << '/'
<< dedominateur << ' ';
numerateur = dedominateur = 0;
}
void Fraction::simplifier(){/*...*/}

  /* prog1.cpp */
#include <iostream>
#include "fraction.h"
using namespace std;
void test(Fraction a, Fraction& b){
Fraction* c = new Fraction(a);
a = b;
b = *c;
c = NULL;
cout<< "F";
return;
}
int main(){
Fraction f1(1,2), f2(2,3), f3(5,4);
Fraction* tab = new Fraction[5];
std::cout << std::endl;
test(f1, tab[2]);
test(tab[3], tab[4]);
f3 = tab[5];
std::cout << std::endl;
return 0;
}

Answer 1

The output with a K obviously comes from the destructor. Two of them would be from the parameter a which is passed by value (copy) to test. The other three are the ones on the first line of main.

The objects created by new are never delete'd, so they are never destructed.